Mechanoluminescence in Scintillators

Scintillating materials generate photons when they are hit by radiations and for this reason are used in high-energy physics to detect particle collisions, in medical imaging or in security devices. Scintillation is an example of Radioluminescence: however there are materials which may exhibit Electroluminescence (photon emission when acted by an electric field) or Mechanoluminescence (photon emission by elastic deformation, fracture or scratch). These phenomena, which are cross- correlated affects the photon production and therefore a deeper knowl- edge of them is needed. As we have already done for non-deformable scintillators, we obtain a continuum model for Mechanoluminescence (in the isothermal and elastic case), which allows to descibe from a phenomenological point of view the experimentally-obtained relations between mechanical stress and scintillation efficiency

Ornithogenic soils on basalts from maritime Antarctica

Large amounts of organic matter deposited by marine birds, especially penguins, accumulate on ice-free areas of maritime Antarctica during the short austral summer. The well-known ornithogenic soils of this region are unique in Antarctica and represent important sites where phosphatization is the main soil-forming process. Most recent studies in ornithogenic soils of maritime Antarctica were conducted on andesitic areas, and no reports are available about ornithogenic soils on basaltic intrusion. The purpose of this study was to report the main chemical, physical, and mineralogical characteristics of ornithogenic soils on basaltic intrusion of Barrientos, and evaluate the effects of different nesting bird species and altitude. The amount of Mehlich-extractable P indicates a close interaction between guano and underlying soils, with different end products depending on altitude, weathering degree and nesting bird species. In the soil collected from the giant petrel's nest, the intensity of organic deposition was much lower. The lower means of Mehlich-extractable P, total organic carbon and total nitrogen in Barrientos Island showed the little influence of marine birds when compared to King George Island. On the other hand, the means of exchangeable Ca and Mg were higher due to the basaltic composition of the regional volcanoes, contrasting with the andesites, which are the commonest rock type in maritime Antarctica. Thus, the soil characteristics of the Barrientos Island are influenced by both parent material and phosphatization

Prevalence of peripheral artery disease by abnormal ankle-brachial index in atrial fibrillation: Implications for risk and therapy

Non-valvular atrial fibrillation (NVAF) is the most common sustained arrhythmia encountered in clinical practice and is associated with a fivefold increased risk for stroke (1). Moreover, patients with NVAF often suffer from atherosclerotic complications such as acute myocardial infarction (AMI) (2). Peripheral artery disease (PAD) is an established marker of systemic atherosclerosis but its prevalence in NVAF is still unclear. We reasoned that inclusion of ankle/brachial index (ABI), which is an established tool for diagnosis of PAD (3), in the CHA2DS2-VASc (4) score would better define the prevalence of vascular disease. To address this issue, the Italian Society of Internal Medicine (SIMI) established an Italian registry documenting ABI in NVAF patients. The Atrial Fibrillation Registry for Ankle-brachial index Prevalence Assessment- Collaborative Italian Study (ARAPACIS) is an independent research project involving all Regional Councils of SIMI. The first objective of the study was to estimate prevalence of ABI 640.90 in NVAF patients. Consecutive patients with NVAF referred to internal medicine wards were eligible for the enrollment. Enrolment started on October 2010 and continued until 30 October 2012 (ClinicalTrials.gov Identifier: NCT01161251). Patients were enrolled if they were 18 years or older and had diagnosis of NVAF, recording during the qualifying admission/consultation or in the preceding 12 months, and if it was possible to obtain the ABI measurement. Exclusion criteria included the following: acquired or congenital valvular AF, active cancer, disease with life expectancy less than 3 years, hyperthyroidism and pregnancy. We initially planned to include 3,000 patients. The Data and Safety Monitoring Board (see appendix) decided to perform an interim analysis to assess the prevalence of ABI in the enrolled populations - as a higher than expected prevalence of low ABI was detected- and decided to interrupt the patients\u2019 enrollment. The sample size was amended as follows: asample of 2,027 patients leads to the expected prevalence of 21% with a 95% confidence interval width of 3.5% (StataCorp LP, Texas, USA). Among the 2,027 NVAF patients included in the study, hypertension was detected in 83%, diabetes mellitus in 23%, dyslipidemia in 39%, metabolic syndrome in 29% and smoking in 15%. At least one atherosclerotic risk factor was detected in 90% of patients. The NVAF population was at high risk for stroke, with only 14% having a CHA2DS2-VASc score 0-1, while 86% had a risk 652. Despite this, 16% were untreated with any antithrombotic drug, 19% were treated with antiplatelet drugs (APs) APs and 61% with oral anticoagulants (OAC); 4% of patients were treated with both APs and OAC. Among AF population, 428 patients (21%) had ABI 640.90 compared to 1,381 patients, who had ABI 0.91-1.39 (69%); 204 patients (10%) had ABI 651.40 (Figure 1). ABI recorded only in one leg was excluded from the analysis (n=14). ABI 640.90 progressively increased from paroxysmal to permanent NVAF (18%, 21%, 24%;p=0.0315). NVAF patients with ABI 640.90 were more likely to be hypertensive (88% vs. 82%;p=0.032), diabetic (34% vs. 20%;p<0.0001) or smokers (20% vs. 14%;p=0.0008), or to have experienced TIA or stroke (17% vs. 10%;p<0.001). NVAF patients with ABI 640.90 had a higher percentage of CHA2DS2-VASc score 652 compared to those with ABI>0.90 (93% vs. 82%;p<0.0001). Logistic regression analysis demonstrated that ABI 640.90 was significantly associated with smoking habit [OR; 95% CI): 1.99;1.48-2.66, p<0.0001], diabetes (1.93;1.51-2.46, p<0.0001), age class 65_74 yrs. (2.05;1.40-3.07, p<0.0001], age class 6575 yrs. (3.12;2.16- 4.61, p<0.0001), and history of previous TIA/stroke (1.64;1.20-2.24, p=0.002). Vascular disease, as assessed by the history elements of CHA2DS2VASc score was recorded in 17.3% of patients; inclusion of ABI 640.90 in the definition of vascular disease yielded a total prevalence of 33%. A higher prevalence of vascular disease was detected if ABI 640.90was included in the CHA2DS2VASc score (Figure 1). CHA2DS2VASc including ABI 640.90 was more associated with previous stroke [43%;OR (95% CL): 1.85 (1.41-2.44), P<0.0001] compared to CHA2DS2VASc with ABI 0.91-1.39 [23%; OR: 1.52 (1.10-2.11), P=0.0117]. To best of our knowledge, there is no large-scale study that specifically examined the prevalence of ABI 640.90 in NVAF. In our population, 21% had ABI 640.90 indicating that NVAF is often associated with systemic atherosclerosis. The CHADS2, has been recently refined with the CHA2DS2-VASc score, which includes vascular disease as documented by a history of AMI, symptomatic PAD or detection of atherosclerotic plaque in the aortic arch (4). Comparison of vascular prevalence as assessed by CHA2DS2-VASc score and/or ABI 640.90 is of interest to define the potentially positive impact of measuring ABI in the management of NVAF patients. Inclusion of ABI 640.90 in the definition of vascular disease greatly increased the prevalence of vascular disease, which increased from 17.3% (based on history alone) to 33% (based on ABI) in the entire population. If ABI 640.90 was encompassed in the definition of vascular disease of CHA2DS2-VASc score the prevalence of vascular disease increased in every risk class. Inclusion of ABI 640.90 in the CHA2DS2-VASc score allowed us better defining of the risk profile of NVAF patients with an up-grading of the risk score in each CHA2DS2-VASc score category. This may have important therapeutic implications if the new score could be tested prospectively, as a higher number of NVAF patients would be potentially candidates for an anticoagulant treatment by measuring ABI. A prospective study is, therefore, necessary to validate the risk score of this new definition of vascular disease. In conclusion, this study provides the first evidence that one fifth of NVAF patients had an ABI 640.90 indicating that it may represent a simple and cheap method to better define the prevalence of vascular disease in NVAF

Predictive factors of response to mTOR inhibitors in neuroendocrine tumours

Medical treatment of neuroendocrine tumours (NETs) has drawn a lot of attention due to the recent demonstration of efficacy of several drugs on progression-free survival, including somatostatin analogs, small tyrosine kinase inhibitors and mTOR inhibitors (or rapalogs). The latter are approved as therapeutic agents in advanced pancreatic NETs and have been demonstrated to be effective in different types of NETs, with variable efficacy due to the development of resistance to treatment. Early detection of patients that may benefit from rapalogs treatment is of paramount importance in order to select the better treatment and avoid ineffective and expensive treatments. Predictive markers for therapeutic response are under intensive investigation, aiming at a tailored patient management and more appropriate resource utilization. This review summarizes the available data on the tissue, circulating and imaging markers that are potentially predictive of rapalog efficacy in NETs

Prevalence of peripheral artery disease by abnormal ankle-brachial index in atrial fibrillation: Implications for risk and therapy

To the Editor: Nonvalvular atrial fibrillation (NVAF) is the most common sustained arrhythmia encountered in clinical practice and is associated with a 5-fold increased risk for stroke (1). Moreover, patients with NVAF often suffer from atherosclerotic complications such as acute myocardial infarction (AMI) (2). Peripheral artery disease (PAD) is an established marker of systemic atherosclerosis but its prevalence in NVAF is still unclear. We reasoned that inclusion of ankle-brachial index (ABI), which is an established tool for diagnosis of PAD (3), in the CHA2DS2-VASc (4) score would better define the prevalence of vascular disease. Toaddress this issue, the ItalianSociety of InternalMedicine (SIMI) established an Italian registry documenting ABI inNVAF patients. The Atrial Fibrillation Registry for the ARAPACIS (Ankle- brachial Index Prevalence Assessment: Collaborative Italian Study) study is an independent research project involving all Regional Councils of SIMI. The first objective of the study was to estimate the prevalence of ABI 0.90 in NVAF patients. Consecutive patients with NVAF referred to internal medicine wards were eligible for the enrollment. Enrollment started in October 2010 and continued until October 30, 2012. Patients were enrolled if they were 18 years or older and had a diagnosis of NVAF, recording during the qualifying admission/consultation or in the preceding 12 months, and if it was possible to obtain the ABI measurement. Exclusion criteria included the following: acquired or congenital valvular AF, active cancer, disease with life expectancy &lt;3 years, hyperthyroidism and pregnancy. We initially planned to include 3,000 patients. The Data and Safety Monitoring Board (Online Appendix) decided to perform an interim analysis to assess the prevalence of ABI in the enrolled populationsdas a higher than expected prevalence of low ABI was detecteddand decided to interrupt the patients’ enrollment. The sample size was amended as follows: a sample of 2,027 patients leads to the expected prevalence of 21% with a 95% confidence interval width of 3.5% (StataCorp LP, College Station, Texas). Among the 2,027 NVAF patients included in the study, hyper- tension was detected in 83%, diabetes mellitus in 23%, dyslipidemia in 39%, metabolic syndrome in 29%, and smoking in 15%. At least 1 atherosclerotic risk factor was detected in 90% of patients. The NVAF population was at high risk for stroke, with only 18% having a CHA2DS2-VASc score of 0 to 1, while 82% had a risk 2. Despite this, 16% were untreated with any antith- rombotic drug, 19% were treated with antiplatelet drugs (APs), and 61% with oral anticoagulants (OAC); 4% of patients were treated with both APs and OAC. Among the AF population, 428 patients (21%) had ABI 0.90 (69%); 204 patients (10%) had ABI 1.40 (Fig. 1). ABI recorded only in 1 leg was excluded from the analysis (n ¼ 14). ABI 0.90 progressively increased from paroxysmal to permanent NVAF (18%, tensive (88% vs. 82%; p ¼ 0.032), diabetic (34% vs. 20%; p &lt; 0.0001), or smokers (20% vs. 14%; p ¼ 0.0008), or to have experi- enced transient ischemic attack or stroke (17% vs. 10%; p &lt; 0.001). 21%, 24%; p ¼ 0.0315). NVAF patients with ABI 0.90 were more likely to be hyper- NVAF patients with ABI 0.90 had a higher percentage of CHA2DS2-VASc score 2 compared with those with ABI &gt;0.90 (93% vs. 82%; p &lt; 0.0001). significantly associated with a smoking habit (odds ratio [OR]: 1.99; 95% confidence interval [CI]: 1.48 to 2.66; p &lt; 0.0001), diabetes (OR: 1.93; 95% CI: 1.51 to 2.46; p &lt; 0.0001), age class 65 to 74 years (OR: 2.05; 95% CI: 1.40 to 3.07; p &lt; 0.0001), age Logistic regression analysis demonstrated that ABI 0.90 was class 75 years (OR: 3.12; 95% CI: 2.16 to 4.61; p &lt; 0.0001), and history of previous transient ischemic attack/stroke (OR: 1.64; 95% CI: 1.20 to 2.24; p ¼ 0.002). Vascular disease, as assessed by the history elements of CHA2DS2VASc score, was recorded in 17.3% of patients; inclu- sion of ABI 0.90 in the definition of vascular disease yielded a total prevalence of 33%. A higher prevalence of vascular disease was detected if ABI 0.90 was included in the CHA2DS2VASc score (Fig. 1). CHA2DS2VASc including ABI 0.90 was more associated with previous stroke (43%; OR: 1.85; 95% CI: 1.41 to 2.44; p &lt; 0.0001) compared to CHA2DS2VASc with ABI 0.91 to 1.39 (23%; OR: 1.52; 95% CI: 1.10 to 2.11; p ¼ 0.0117). To the best of our knowledge, there is no large-scale study that specifically examined the prevalence of ABI 0.90 in NVAF. In our population, 21% had ABI 0.90 indicating that NVAF is often associated with systemic atherosclerosis. The CHADS2 has been recently refined with the CHA2DS2- VASc score, which includes vascular disease as documented by a history of AMI, symptomatic PAD, or detection of atheroscle- rotic plaque in the aortic arch (4). Comparison of vascular prevalence as assessed by CHA2DS2- NVAF patients. Inclusion of ABI 0.90 in the definition of vascular disease greatly increased the prevalence of vascular disease, which increased from 17.3% (based on history alone) to 33% (based compared with 1,381 patients, who had an ABI of 0.91 to 1.39 to better define the risk profile ofNVAFpatients with an up-grading of the risk score in each CHA2DS2-VASc score category. This may have important therapeutic implications if the new score could be tested prospectively, as a higher number of NVAF patients would on ABI) in the entire population. If ABI 0.90 was encompassed in the definition of vascular disease of CHA2DS2-VASc score the prevalence of vascular disease increased in every risk class. Inclusion of ABI0.90 in theCHA2DS2-VASc score allowed us VASc score and/or ABI 0.90 is of interest to define the poten- tially positive impact of measuring ABI in the management of potentially be candidates for an anticoagulant treatment by measuring ABI. A prospective study is, therefore, necessary to validate the risk score of this new definition of vascular disease. In conclusion, this study provides the first evidence that one-fifth of NVAF patients had an ABI 0.90, indicating that it may represent a simple and cheap method to better define the prevalence of vascular disease in NVAF